title: Very late effects of dual chamber pacing therapy for obstructive hypertrophic cardiomyopathy.
abstract: BACKGROUND
  The very long-term effects of dual chamber pacing as a primary treatment for hypertrophic obstructive cardiomyopathy (HOCM) are poorly known and controversial.
  
  
  OBJECTIVE
  To examine the intermediate- and long-term clinical and haemodynamic effects of permanent dual chamber pacing in patients presenting with HOCM.
  
  
  METHODS
  Between 1991 and 2007, 51 patients (mean age 59 ± 14 years) presenting with HOCM and New York Heart Association (NYHA) functional class ≥ II despite optimal medical therapy underwent implantation of DDD pacemakers with or without a defibrillator and were followed for 11.5 years (range 0.4-21.8 years).
  
  
  RESULTS
  During follow-up, no patient underwent myectomy or septal alcohol ablation. NYHA functional class and other disease manifestations decreased significantly over 1-2 years of follow-up and remained stable thereafter. The left intraventricular (LV) gradient decreased by a mean of 78% over 1-2 years, reaching 89% at end of follow-up, along with disappearance of systolic anterior motion of the mitral valve. Mean LV ejection fraction decreased from a mean of 64 ± 8% before pacing to 56 ± 9% at end of follow-up (P=0.05), while LV end-diastolic diameter did not change significantly. The 5- and 10-year actuarial survival rates were 90% and 65%, respectively. Among 22 deaths, 10 were due to cardiovascular and 12 to non-cardiovascular causes; two patients underwent cardiac transplantation after 8 and 13 years of DDD pacing, respectively.
  
  
  CONCLUSIONS
  In this sample of patients with HOCM, DDD pacing alleviated symptoms and improved haemodynamic function over the very long term. The merits of this treatment should be revisited in a controlled trial.
authors.affiliation: Cardiology Division, Rennes University Hospital, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Lucon
authors.forename: Laurent
authors.initials: L
authors.lastname: Palud
authors.forename: Dominique
authors.initials: D
authors.lastname: Pavin
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
authors.forename: Nathalie
authors.initials: N
authors.lastname: Behar
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.forename: Philippe
authors.initials: P
authors.lastname: Mabo
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daubert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D016009:Chi-Square Distribution; D017147:Defibrillators, Implantable; D004867:Equipment Design; D005260:Female; D016027:Heart Transplantation; D006439:Hemodynamics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011474:Prosthesis Design; D020127:Recovery of Function; D012189:Retrospective Studies; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D055815:Young Adult
keywords: AV; Cardiomyopathie hypertrophique obstructive; Cardiomyopathy; Dual chamber pacing; HOCM; Heart failure; Hypertrophic obstructive cardiomyopathy; ICD; Insuffisance cardiaque; LV; LVOT; NYHA; New York Heart Association; RV; Stimulation cardiaque double-chambre; Traitement électrique; atrioventricular; hypertrophic obstructive cardiomyopathy; implantable cardioverter defibrillator; left ventricular; left ventricular outflow tract; right ventricular